Jason senses Sleeper offering a mental hand to Dylan. In response, he lowers his mental and emotional guards to show his own willingness to help.

It's only because of how much he trusts Sleeper and Dylan that he's willing to be part of a hive mind. It's not being used for manipulation or abuse. For situations like these, it can be supportive and comforting. Just having even just one extra voice could make a difference.